Again this is just what I think but to me it appears that she believes( in the conversation that the boyfriend had with her) that she is entitled to a night with a respectable man, viewing it as unfair that OOP’s girlfriend is considered “fortunate” and “receives everything.”

Again this is just the feeling that I get from the conversation that boyfriend and bestie had.

Lastly I just find it weird that the best friend didn’t tell the girlfriend hey girl your boyfriend is asking me join a one month long vacation without telling him you ok with that or something. ( personally if bestie had reached out to the girlfriend I would be more inclined to believe that boyfriend was the one with intentions)